Fig. 4

Example of using temperature–depth profile data to determine onset of Pacific cod migration from release area (Nazan Bay). Temperature observations A for geolocated fish (Tag 178690, Tag 178704) match the stationary tag data and two fish (Tag 178702 and Tag 178705) that experienced post-tagging mortality in the release area until likely dates of departure (dashed vertical lines, magenta = Tag 178690, orange = Tag 178704). Temperature observations from geolocated fish B were similar (i.e., within 0.2 °C) to stationary reference tags despite depth changes of more than 100 m, while fish likely occupied release areas